1895. Discovery of X-rays. Researchers and scholars are true martyrs, because they do not know how to protect themselves against radiation dermatitis. Professor Belcour has to have one hand amputated, his assistant Henri Vermont, aware of the danger, has the courage to break up with his fiancée. Withdrawn to the countryside, they eventually recover.
The son of a ruined family transforms into a castellan following an inheritance, becomes a parachutist champion in spite of himself, and becomes famous.
During the French Revolution in 1793, a member of the Convention, seduced by the Comtesse de Beaulieu, helps her to discover the truth about the relationship between Agnès de Fitz-James and the count who was guillotined.
